Safety shutoff device for carbonaceous fuel burners



Nov. 15, 1949 w. H. ROBINSON 2,488,330

SAFETY SHUTQFF DEVICE FOR CARBONACEOUS FUEL BURNERS Filed D90. 14, 1946 2 Sheets-Sheet l IN V EN TOR. WILLIAM H. ROBINSON Nov. 15, 1949 w. H. ROBINSON 2,438,330

SAFETY SHUTOFF DEVICE FOR CARBONACEOUS FUEL BURNERS Filed Dec. 14, 1946 2 Sheets-Sheet 2 IN V EN TOR. WILLIAM H. ROE/V50 ATTK Patented Nov. 15, 1949 UNITED STATES PATENT v OFFICE SAFETY SHUTOFF DEVICE FOR CARBO- NACEOUS FUEL BURNERS This invention relates to safety devices for combustion systems utilizing carbonaceous fuels and especially illuminating gas, including liquefled petroleum gases.

In many types of domestic, commercial, and industrial devices and appliances such as space heaters and furnaces, automatic hot water heat- .ers, and fuel-burning refrigerators, all hereinafter referred to as appliances, flues are provided which so affect the flames of said appliances that the flames thereof are normally directed in predetermined paths. Concerning many popular types of automatic domestic hot water heaters and both kerosene and gas refrigerators especially, they are provided with self-contained flues to properly conduct and direct the flames thereof and such appliances are very frequently otherwise unvented in that they are not connected with a flue or chimney leading to the outside atmosphere.

Where these so-called unvented appliances are provided with self-contained flues for definitely directing the flames thereof, said flues, after fairly extensive use, not infrequently become clogged due to gradual accumulation of carbon, corrosion, and other foreign matter. It has been discovered that such clogging of the flue causes improper combustion of the flame due to the same being deprived of sufficient oxygen for secondary combustion, and rather than travel in its normal predetermined path, the flame will digress therefrom and, in a more or less lazy wandering way, ambulate around above the burner while seeking additional oxygen.

This ambulatory flame in connection with gasconsuming appliances gives oil? a dangerous percentage of an incompletely burned gas, carbon monoxide, which escapes into living and other quarters wherein appliances of this nature are located, said condition being injurious and even toxic to humans. In many instances in connection with both gas and liquid fuel oil-burning .appliances, such a condition damages the appliance inasmuch as the flame when wandering from its predetermined path is suflicient to injure at least certain portions of appliances when contacted by the flame and otherwise creates a fire hazard.

As far as is presently known, no safety means have previously been provided for purposes of automatically preventing the escape of such dangerous and toxic gases of primary combustion into living quarters especially, as well as any others housing such appliances.

It is therefore an object of the present invenfrigerators.

tion to provide an automatically functioning safety shut-off system utilizing heat-sensitive means which will respond to the heat of ambulatory flames of primary combustion emanating from improperly functioning appliances, said means being so positioned in appliances utilizing carbonaceous fuels that the fuel supply to the combustion zones of such appliances is automatically shut off.

It is a further object of the invention to provide several types of heat-sensitive means which may be selectively used within the above-described safety system.

The details of these objects and of the invention, as well as other objects thereof are set forth hereinafter and illustrated in the accompanying drawings in which:

Fig. 1 is a partially sectionalized side elevation of an exemplary gas burner system embodying the principles of the present invention.

Fig. 2 is a sectionalized side elevation of another embodiment of one element comprising the present invention.

Fig. 3 is a sectionalized side elevation of still another embodiment of said element.

Fig. 4 is a side elevation, partly in section, of a skeletonized exemplary system embodying the principles of the present invention.

Fig. 5 is a sectional elevation of another embodiment of one element comprising the present invention.- I

Fig. 6 is a perspective fragmentary view of a detail of the structure shown in Fig. 5.

Fig. 7 is a side elevation, partly in section, of another exemplary system embodying the principles of the present invention.

To best illustrate and describe the principles of the present invention, several types of appliances utilizing illuminating gas have been selected as exemplary of a large variety of diflerent types of appliances of both the vented and unvented types using carbonaceous fuels.

A large proportion of gas-utilizing appliances of the unvented type comprise "so-called gas re- Application of the principles of this invention to a gas refrigerator is shown in Figs. 1 through 4.

Referring to Fig. 1, a gas burner ID of conventional refrigerator type is mounted so as to be directed into a generator tube I2 leading to a flue it shown in Fig. 4.

To insure that accidental extinguishing of the flame I6 will not result in free escape of unburned gas from the burner, a. safety device is provided in unit I8 of which the burner l0 comprises. a

part. A valve seat 28 when heated, valve 24 is maintained open.

is provided in the gas conduit 22 of said unit l8. A safety valve 28 is mounted for movement relative to said seat, one end of said valve being secured to a flexed or bowed bi-metallic' thermostatic disc 28 of whichfione commercialtype is sold under the name Klixonfi Said disc is mounted within a i ring. 28 integrally secured to a heat transfer invention canbe readily appliedtosuch conventional burner unit's'by attaching to-the inlet end 'a' thereof a specialunit containing a valve similar to valve 82. One such special unit 88 is shown in flame I8 becomes extinguished, disc 28 will quick- 1 the present illustration, per se, is not novel.

After fairly extensive use, tube i2 or flue M will become partially or completely clogged, un-

1 less regularly'serviced, as indicated at 82. Clogging of this nature will cause the flame to digress or ambulate in a somewhat slow, lazy manner out of its predetermined path as indicated in dotted lines at 84. Such digression-or ambulation admirably serves to eifect the principles of the present invention, since the generation of in- Jurious amounts of carbon monoxide generally 1 v commences when ambulation of the flame originates.

Either as a separate unit 88 or 88, or as part of a unit such as i8, an extra safety Klixon type valve embodying elements similar to 24, 28, 28,

88 is embodied in the inlet end of the unit l8 for example, said extra Klixon acting reversely, however, to the first-mentioned one. That is, valve seat 48, valve 42, ring 44, and heat transfer member 48 are similar to corresponding parts of unit i8, but the bi-metallic disc 48 acts-reversely to disc 28 in that disc 48 acts to open the valve when unheated but close said valve when heated. Thus, when flame l8 digresses from its predetermined path shownin full lines to an ambulatory path such as shown in dotted lines at 84, the

heat therefrom, even though mainly only a primary combustion flame, will serve to close valve 42 and thus extinguish flame 84.

While digressing, flame 84 will generally be sumcient to maintain valve 24 open. However, closing of valve 42 by the digressing flame 84 will extinguish said flame, thus causing valve 24 to close. Resulting cooling, of member 48 will rapidly cause valve 42 to reopen but, since valve 24 will be closed by that time or at most, a moment later, no appreciable amount of so-called raw gas will escape into the living or other quarters in which the appliance may be located.

When the flame of a refrigerator burner is extinguished in this manner, refrigeration within the appliance soon ceases and the user's attention is directed to the factfthat a malfunc- V tioning exists and a serviceman, capable of debodiment of the invention as applied to a gas refrigerator, it will be seen that the escapeof dangerous carbon monoxide is halted before appreciable harm is done.

In Fig. 1 is illustrated an unconventional burner unit embodying not only conventional safety valve but also valve 42 comprising, both "in itself and in conjunction with valve 24, one

important embodiment of the instant invention. Since many gas refrigerators are presently in 8 use embodying burner units similar to l8 but not including valve 42 and its related members, the

ly reversely flex to close valve 24. This much of v Fig-2 and another unit 88 is shown in Fig. 8. Unit 88 is provided with an integral, externally threaded end 88 which can be readily attached to said inlet end of conventional valve unit i8,- and the gas supply conduit issecured to internally threaded end 82 of unit 88. Details of the valve and heat conductive members in units 88 and 88 are similar in design and function to valve 42 and its related parts. 7 r

In unit 88, the inlet end 84 and outlet end 88 can, as shown, be at right angles to each other and a, securing member 88 can be attached there;

upon the requirements of the particular application at hand. However, inmost circumstances, the disc 48 will probably be one-to function at a lower temperature than disc 28. Notwithstanding this,.the temperature of operation 'of disc 48 will obviously have to be higher-than the temperature of the adjacent body portion of any of units I8, 88, or 88 resulting from normal functioning of flame l8.

Not only can the temperature of operation of disc 48 be selected for the aforesaid purposes, but it is also possible to so select an operating temperature for said disc that, ifa back flash develops within burner Hi, the excess heating of the burner ill will be quickly transmitted through the body of unit l8 to disc 48 and cause the same to function and close valve 42, thereby extinguishing the back flash within burner i8 by shutting off the gas supply to said burner. Back flashes also generate obnoxious and sometimes dangerous fumes. Subsequent closing of valve 24 will be effective in the manner described above.

To illustrate another type of-heat sensitive element which may be used equally as readily as the bi-metallic disc type illustrated in Figs. 1 through 3, there is shown in Fig. 5a pressureactuated type, responsive to the expansion of a gas or fluid, for closing a safety valve. Specifically, the valve unit 88 has a body having an inlet end 82 and an outlet end 84. Valve seat 88 receives valve 88 to close passage through the unit; Valve 88 is carried on one end of a valve rod 18 which is spring biased in valve closing direction but is normally restrained therefrom by a transversely acting spring-biased sear or latch I2 having an opening 14 receiving rod 18 and also having projecting thereinto a latch dog 18 clearly illustrated in detail in Fig. 6. Said dog normally engages an annular shoulder 18 on rcd'lii to hold valve 88 in retracted position. Rod 18 is'guided by-spaced'bearings shown in Fig. 5 and passage of gas to the upper portion of the valve unit is prevented by flexible diaphragm 1| rimof the aeeasso and bulb are filled with a suitable expausible gas or fluid. A valve of this nature is particularly advantageous in applications where it is desired to have the shut-off valve in the supply line at a position remote from that Where the heat of the flame of an appliance is apt to migrate or digress. An application of this type is shown in Fig. '7 in an exemplary manner. The valve 68 is disposed in the gas supply line to one type of domestic hot water heater 8%,- but without limitation thereto.

In the type hot water heater shown in Fig. 7, preferably a plurality of vertical tubes or fiues til extend up one side of the water tank 9 l, and heat is reflected from said tubes toward said tank by a suitable reflector 95. Heat passes therefrom through a header 95 which may, if desired, be connected to a chimney. Water heaters of this nature generally have a relatively low input and need not necessarily be connected to a chimney. iior this reason especially, the principles of the safety features of the present invention are highly applicable to this type of heater inasmuch as they are frequently disposed in kitchens, bathrooms, and other living quarters.

The burner 92 of such an appliance, when lines 533 are not clogged, will normally be directed upward into said flues. If thefiues are sufiiciently clogged, however, the flame will digress from its normal path and ambuiate through ports such as 95' in the burner housing, the flame assuming a path, for example, as that shown by dotted lines 98 in Fig. 7. In such an application, a valve unit of the type shown in Fig. is highly applicable since the bulb 36 thereof may be disposed so as to be readily contacted by a migrating or digressing flame and the heat therefrom will actuate valve unit 68 to shut off the gas supply to the burner 92. Bulb 86 may be suitably supported in an appropriate position by means such as a bracket MB. In systems of this nature, it is customary that the valve unit Gil be placed in the line between the burner and the usual manual shut-off valve 96 shown in Fig. '7.

In addition to the pressure actuated valve shown in Fig. 5 and the bi-metallic thermostatic type valves shown in Figs. 1 through 3, it is readily conceivable and within the purview of this invention that the principles thereof can include in lieu of said afore-mentioned type valves either another valve involving electromagnetic and thermocouple principles or still another type utilizing a diaphragm actuated valve activated by other suitable heat-sensitive mechanism.

Further, the condition referred to hereinabove regarding a clogged flue is not the only condition which will induce the formation of dangerous or obnoxious gas. For example, overgassing, a condition wherein there is too much gas for combustion release, will cause carbon monoxide to be produced. Also, a strong down-draft in an appliance connected to the outside atmosphere by a chimney or otherwise will likewise cause improper secondary combustion, resulting in the formation of carbon monoxide. The present invention serves to prevent appreciable formation of such dangerous gas resulting from these conditions.

While the invention has been illustrated and described in its several preferred embodiments and has included certain details, it should be understood that the invention is not to be limited to the precise details herein illustrated and de- What I claim is:

1. A safety shut-off for a combustion system utilizing carbonaceous fuel and comprising in combination, a burner, a fuel supply system connected to and arranged to supply fuel to the combustion zone of said burner, a combustion vent adjacent said burner and normally directing a flame from said burner in a substantially predetermined path, a shut-off valve in said supply conduit, heat-sensitive means interconnected to said valve, and means supporting said heat-sensi tive means in a position to respond to heat from said flame when digressing from said predetermined path thereof and said heat-sensitive means being constructed and arranged to close said valve in response to said heat when emanating from said digressing flame.

2. A safety shut-off for a combustion system utilizing carbonaceous fuel and comprising in combination, a burner, a fuel supply system con nected to and arranged to supply fuel to the combustion zone of said burner, a combustion vent adjacent said burner and normally directing a flame from said burner in a substantially predetermined path, a shut-off valve in said supply conduit, heat-sensitive expansible means interconnected to said valve, and means supporting said heat-sensitive expansible means in a position to respond to heat from said flame when digressing from said predetermined path thereof and said heat-sensitive means being constructed and arranged to close said valve in response to said heat when emanating from said digressing flame.

3. A safety shut-off for a combustion system utilizing carbonaceous fuel and comprising in combination, a burner, a fuel supply system connected to and arranged to supply fuel to the combustion zone of said burner, a combustion vent adjacent said burner and normally directing a flame from said burner in a substantially predetermined path, a shut-off valve in said supplf conduit, lei-metallic thermostatic meansinterconnected to said valve, and means supporting said bi-metallic thermostatic means in a position to respond to heat from said flame when digressing from .said predetermined path thereof and said heat-sensitive means being constructed and arranged to close said valve in response to said heat when emanating from said digressing flame.

a. A safety shut-off for a combustion system utilizing carbonaceous fuel and comprising in combination, a burner, a fuel supply system connected to and arranged to supply fuel to the combustion zone of said burner, a combustion vent adjacent said burner and normally directing a flame from said burner in a substantially predetermined path, a plurality of shut-off valves connected in series in said supply conduit, heat-sensitive means arranged to be heated by said flame when disposed in its predetermined path and operably connected to one of said valves to maintain it open when so heated but constructed so as to close said valve when said means is not so heated, a second heat-sensitive means interconnected to the other valve, and means supporting said second heat-sensitive means in a position to respond to heat from said flame when digressing from said predetermined path thereof and said heat-sensitive means being constructed and arranged to operate the other valve so as to close it scribed since the same may be carried out in in response to said heat emanating from said flame when digressing from said predetermined path thereof but maintain said other valve open when said flame is disposed in said path.

. 7 5. A safety shut-ofi for a combustion system utilizing carbonaceous fuel and comprising in combination, a burner, a fuel supply system connected to and arranged to supply fuel to the com- 'heated by said flame when disposed in its predetermined path and operably connected to one of said valves to maintain it open when so heated but constructed so as to close said valve when said means is not so heated, a second bi-metallic thermostatic means interconnected to the other valve, and means supporting said second bi-metallic thermostatic means in a position to respond to heat from said flame when digressing from said predetermined path thereof and said heat- 7. A safety shut-oil. for a combustion system utilizing illuminating gas and comprising in combination, a burner; a gas supply conduit connected to and arranged to supply gas to the combustion zone of said burner, a generator tube ar-. ranged with its inlet end adjacent said burner so as to "direct a flame of said burner in a predetermined path into said tube, a, plurality of shut-oi! valves connected in series in said conduit, bimetallic thermostatic means positioned to be heated by said burner flame when disposed in its predetermined path and operably connected to oneof said valves to maintain it open when so sensitive means being constructed and arranged to operate the other valve so as to close it in response to said heat emanating from said flame when digressing from said predetermined path thereof but maintain said other valve open when said flame is disposed in said path.

6. A safety shut-off for a combustion system utilizing illuminating gas and comprising in combination, a burner, a gas supply conduit connected to and arrangedto supply gas to the combustion zone of said burner, a generator tube arranged with the axis of its inlet end substantially horizontal and said end adjacent said burner so as to direct a flame of said burner in a predetermined path into said tube, a shut-off valve in said conduit, bi-metallic thermostatic means interconnected to said valve, and means supporting said thermostatic means in a position adjacent and above said inlet end of said tube in which position it will be affected by heat from a flame of said burner to close said valve when said flame 'digresses from its said predetermined path into an upwardly directed path substantially lateral.

to said predetermined path as when said generator tube becomes sufliciently clogged to cause said flame to digress into said lateral path.

heated but also constructed to close said valve when not so heated, a second bi-me'tallic thermostatic means interconnected to the other valve. and means supporting said second thermostatic means in a position adjacent said inlet end of said tube in which position it will be affected by heat from a flame of said burner to close said other valve when said flame digresses from its said predetermined path into a path substanitally lateral to said predetermined path as when said generator tube becomes sufiiciently clogged to cause said flame to digress into said lateral path.

WILLIAM H. ROBINSON.

' REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Breese May 16, 1944 

